1. Field of the Invention
This invention relates generally to improving the heat dissipation of components assembled on a substrate, and more particularly to providing a thermally reliable attachment of a heat dissipation device to multiple electrical components on a substrate, while maintaining vibration isolation between the heat dissipation device and the multiple electrical components.
2. Description of the Prior Art
In many data processing systems (e.g., computer systems, programmable electronic systems, telecommunication switching systems, control systems, and so forth) one or more electrical components (e.g., central processing unit chips, and other integrated circuit chips operating at very high frequencies) individually dissipate a considerable amount of heat during operation. If the heat dissipation mechanism for cooling such a high power dissipation component is not adequate, then the temperature of the high power dissipation component will quickly rise to a temperature that results in either temporary or permanent operational failure of that component, and typically failure of the entire data processing system dependent on that component.
The industry standard package styles for high power dissipation electrical components frequently consist of ceramic body pin grid arrays (PGAs) for through-hole substrates, or ceramic surface mount equivalents (e.g., land grid array components, ball grid array components, and so forth) for surface mount substrates. The body of an electrical component is frequently thermally coupled to a heat dissipation device (e.g., a heat sink, a heat-pipe, a fluid cooling system, a cooling fan, or other equivalent devices).
A special type of heat-pipe known as a vapor chamber is sometimes used when a large amount of heat dissipation capability is required for a processor chip or other high power dissipation component. A vapor chamber is a relatively expensive single point-of-failure for an electrical component. The failure of a vapor chamber is so catastrophic for an electrical component that a considerable amount of money is spent in fabricating reliable vapor chambers. However, a serious reliability problem has emerged with vapor chambers, since there is no redundant heat conduction path to provide substitute heat dissipation if the vapor chamber fails to operate.
Conventional solutions for this problem involve a variety of unattractive remedies. The most obvious conventional solution is to attach large heat sinks to each high power dissipation component. Unfortunately, this kind of heat dissipation solution taxes the data processing system design with new constraints. Large individual heat sinks on high power dissipation components will block cooling airflows, and require a reduced packing density of components on each substrate, or even a reduced packing density of substrates in the data processing system. The attachment of large individual heat sinks on high power dissipation components can also transmit large vibrational forces to the leads of the components, eventually breaking some electrical connections between the component leads and the substrate. Furthermore, the attachment of separate large heat sinks on high power dissipation components would not eliminate the problems caused by vapor chamber failures, but only reduce the severity and frequency of occurrence of the problems caused by vapor chamber failures.
FIG. 1 illustrates two conventional heat dissipation devices attached to two components 218, 219 that are attached to a substrate 220. Each heat dissipation device comprises a vertically stacked plurality of rectangular heat dissipation fins 108, which are enclosed by a hardware structure 114. The hardware structure 114 includes two or more walls 118 (one is shown), and the hardware structure is typically fabricated of the same metal as the heat dissipation device. The hardware structure 114 holds a plurality of screws 120 (typically four long screws are used) and screw springs 111 to attach a base 106 of the heat dissipation device to the substrate 220.
What is needed is an attachment to thermally connect a heat dissipation device to multiple components while maintaining vibration isolation between the heat dissipation device and the multiple components. What is also needed is a heat dissipation device that can use supply redundant, fault-tolerant heat dissipation, instead of using a single vapor chamber for heat dissipation.
The present invention provides an attachment to thermally connect a heat dissipation device to multiple components while maintaining vibration isolation between the heat dissipation device and the multiple components. The present invention also provides a heat dissipation device that can supply redundant, fault-tolerant heat dissipation, instead of using a single vapor chamber for heat dissipation.
A first aspect of the invention is directed to a method to assemble a plurality of components on a substrate to a heat dissipation device. The method includes attaching a channeled base to the heat dissipation device; thermally attaching one or more heat-pipes to the channeled base; placing the heat dissipation device and the channeled base on the plurality of components on the substrate; and physically attaching the heat dissipation device to the substrate, wherein the heat dissipation device channeled base includes one or more heat-pipes thermally coupled to a component of the plurality of components.
A second aspect of the invention is directed to a method to assemble a plurality of components on a substrate to a heat dissipation device containing one or more heat-pipes. The method includes attaching a base to the heat dissipation device; thermally attaching one or more heat-pipes to the base; placing the base of the heat dissipation device on the plurality of components on the substrate; and attaching the base of the heat dissipation device to the substrate, wherein the heat dissipation device base includes one or more heat-pipes to substantially attain an isothermal heat dissipation device base.
A third aspect of the invention is directed to an assembled substrate with a plurality of electrical components attached to a common heat dissipation device. The assembled substrate includes a substrate; a plurality of electrical components attached to the substrate; a heat dissipation device attached to the plurality of electrical components, wherein the heat dissipation device includes one or more heat-pipes inside the heat dissipation device.
These and other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.